What?? Which name is really yours?

I spend hours trying to figure out a family that seemed to have two fathers when finally I determined the two fathers were actually one and he used two different names.  He used Roth on his death certificate and on two of the federal censuses.  He used Rhode on two censuses.  His daughters used Rhode on their official documents.  Once I had it all figured out it was time to fix the genealogy program.  One daughter was entered three times.  Once with each of the names her father used and once with her step-father's name.  It was so confusing it corrupted my data.  Seriously.  Good thing I had backed up an hour earlier.  I hated losing that hour of work but it was better than losing more!  I still wonder why he used two names.